Quite likely not shingles, then. The virus concentrates on one side of the abdomen or the other, sometimes the face (horrible infection there.) Someone posted soon after your post about another sort of broader body 'rash' - too tired to remember.
Certainly your treatment was not in vain. Incidentally, heat rash is a bit of a misnomer, not necessarily associated with heat and sweating.
The bumps were on one side...